Re: PATCH: 0/6 [2nd try]: Add AVX support

Nathan Froyd
2010-03-07T19:10:05Z

On Sun, Mar 07, 2010 at 08:40:10AM -0800, H.J. Lu wrote:
> My first approach works here since XMM and YMM register have the same
> register numbers. We can solve it with 2 alternatives:
>
> 1. Give a different DWARF register number for YMM register,
> which is an incompatible ABI change.
> 2. Implement YMM registers as a super set of XMM registers, which
> is my first approach.

The third alternative--again, what's adopted for the PPC SPE 64-bit
registers--is to give %ymmNh their own DWARF register numbers. I
suppose it's also ABI-incompatible, but it seems like it fits with your
approach much better than either of the above alternatives.

-Nathan